The present invention relates to an automatic programming apparatus capable of obtaining an accurate development diagram by carrying out interference simulation and inverse simulation based on a solid figure while displaying a sheet metal development diagram and its perspective view interlockingly on the same screen.
Recently, line control system has been applied to machine tools (bending machine, laser machine, punching machine, etc.). In such a line control system, as shown in FIG. 1, an automatic programming apparatus (CAE) 1 having CAD/CAM function and a host machine 2 which is a server are disposed in office and these high order apparatuses are connected to machine tools (NCT/laser, bender) on site as lower order apparatus through LAN via a terminal 3, terminal 4 and NC unit 5.
An operator generates a development diagram by imaging a solid figure in the brain based on three side views using CAD function of the automatic programming apparatus 1 so as to obtain a processing program for NCT/laser. After that, with the CAM function, an appropriate tool is allocated for a development diagram generated by the CAD or a laser trajectory is obtained, and such a processing program is transmitted to the host machine 2.
An elongation value is used for generation of the aforementioned development diagram. This elongation value is determined depending on the characteristic of a bender for use and a condition particular for user by referring to an elongation value table.
However, in the conventional automatic programming apparatus, an operator must generate a development diagram by imaging its perspective view in his mind. Therefore, there is a problem that nobody except a skilled operator can generate an accurate development diagram easily if the solid figure is complicated.
Further, because the conventional development diagram has been generated to obtain a processing program for NCT/laser, it cannot be used for a bender if no appropriate treatment is performed, so that it has not been transmitted to the bender.
Further, a preferred development diagram is an accurate development diagram considering interferences between flanges and between a flange and dies. Although the conventional development diagram is produced based on an elongation value table, a preferred development diagram is a development diagram considering actual elongation values on site.
That is, because, in the conventional automatic programming apparatus, the interference with respect to flanges and dies is not checked on CAD side and the development diagram is generated by operator""s imaging a solid figure in his mind by using the elongation values table based on the elongation value, table, there is a problem that no accurate development diagram corresponding to on-site condition can be obtained.
Accordingly, it is an object of the present invention to provide an automatic programming apparatus capable of obtaining an accurate development diagram considering an actual elongation value on site and an interference with respect to flanges and dies easily on the CAD side.
To achieve the above object, according to an aspect of the present invention, there is provided an automatic programming apparatus wherein respective planes constituting a solid input from a two-dimensional three-side view drawing are displayed on a screen; when a reference plane and a butting plane are specified within the respective planes, a temporary development diagram in which the butting plane is butted to the reference plane; a solid figure is generated by bending the temporary development diagram based on a bending condition and displayed interlockingly in a region different from the temporary development diagram; and a development diagram obtained by extracting external frame loop and bending lines of the temporary development diagram is transmitted to CAM on a preceding step, the automatic programming apparatus comprising: graphic editing portion for computing for an interference between respective solid planes of the solid figure so as to notify an interference plane and an interference region of the interference plane as a result of the interference computation; inverse simulation portion for carrying out inverse simulation with specifying dies in succession from a final bending line of the solid figure to carry out the interference computation so as to notify a plane interfering with a die as a result of the interference computation; temporary development diagram correcting portion for reading the results of the interference computations of the graphic editing portion and the inverse simulation portion and correcting the temporary development diagram based on the results of the interference computations; and solid figure generating portion for regenerating a solid figure based on the corrected temporary diagram each time when the temporary development diagram is corrected.
In a preferred embodiment of the present invention, the automatic programming apparatus comprises a plane synthesizing portion for when a side of each of two planes from three planes is specified, regarding one of the two planes as a reference plane and the other plane as a butting plane, butting the specified side of the reference plane with the specified side of the butting plane while possessing an overlapping region corresponding to an elongation value and obtaining the temporary development diagram in which bending lines are entered into the overlapping region; the solid figure generating portion for bending the temporary development diagram expressed on two-dimensional coordinates by affine transformation on three-dimensional coordinates and generating a surface model by attaching a sheet thickness to a shape obtained by bending the temporary development diagram; and perspective view generating portion for erasing shade planes of the surface model obtained by the solid figure generating portion and displaying specified planes in specified colors.
In a preferred embodiment of the present invention, attribute information is attached to the temporary development diagram and the surface model.
In a preferred embodiment of the present invention, the automatic programming apparatus further comprises elongation value information reading portion for determining whether or not there is bending attribute information coinciding with an input bending condition including an elongation value in attribute information file and if that information exists therein, setting the elongation value in the plane synthesizing portion; and finite element method portion for, when it is determined that the bending attribute information does not exist by the elongation value information reading portion, carrying out bending simulation according to elastoplasticity finite element method based on the bending condition, setting an elongation value obtained by the bending simulation in the plane synthesizing portion and storing the elongation value in the attribute information file.
In a preferred embodiment of the present invention, the automatic programming apparatus further comprises a data transmission/reception portion for carrying out transmission and reception of information with a host machine connected through a line.
Further, to achieve the above object, according to another aspect of the present invention, there is provided a computer-readable storage medium for storing a graphic data generation program comprising the steps of: displaying three faces constituting a solid input according to a two-dimensional three-side view drawing on a screen; when a reference plane and a butting plane are specified within the three faces, obtaining a temporary development diagram by butting the butting plane with the reference plane while possessing an overlapping region corresponding to an elongation value; affine-transforming, on three-dimensional coordinates, the temporary development diagram expressed on two-dimensional coordinates; generating a surface model by attaching a sheet thickness to a shape obtained by the affine transformation; erasing shade planes on the surface model and indicating specified planes with specified colors; carrying out interference computation on respective solid planes in the solid figure so as to notify an interference plane and an interference portion of the interference plane as a result of the interference computation; carrying out inverse simulation with specifying dies in succession from a final bending line of the solid figure to carry out the interference computation so as to notify a plane interfering with a die as a result of the interference computation; reading the results of the interference computations of the graphic editing step and the inverse simulation step and correcting the temporary development diagram based on the results of the interference computations; regenerating a solid figure based on the corrected temporary diagram each time when the temporary development diagram is corrected; and generating a development diagram by extracting an external frame loop of the corrected temporary development diagram and bending lines.